Changes in lipid patterns associated with neoplastic cell transformation will be studied in a number of transplantable animal tumors, such as Novikoff hepatomas, series of Morris hepatomas, Ehrlich ascites tumors, in human cancer tissues, and in Novikoff and other tumor cells grown in tissue culture. Emphasis will be placed on unusual lipid constituents whose changes in structure, composition or quantity can be correlated with rapid proliferation or degree of differentiation. In continuation of current work, initial interest will be concentrated on diol lipids and lactic acid-derived lipid constituents. We have found both at increased levels, particularly in poorly differentiated, rapidly growing tumors. Phospholipids derived from short-chain diols are of special interest in view of their strongly hemolytic activity. Possibly reflecting enhanced glycolysis, lactic acid-bound lipid constituents amount to up to 20% of certain tumor phosphorylcholine fractions. The structures of these unusual lipid constituents will be studied in detail and their distribution in tumor, host, and control tissues, in plasma membranes, and in other subcellular fractions will be determined. Their pathways of biosynthesis and enzymatic degradation will be establashed. Knowledge gained through structural, analytical and metabolic studies of malignancy-dependent lipid constituents will be applied to correlate alterations in lipid composition and metabolism with such cancer-related phenomena as disorderly and rapid cell growth, invasiveness, changes in cell morphology, surface properties, membrane permeability and transport, and possibly with immunochemical alterations.